题目:一个整型数组里除了两个数字之外，其他的数字都出现了两次。请找出这两个只出现一次的数字。要求时间复杂度是O(n)，空间复杂度是O(1).
核心代码:
<pre><code>`
// 1首次出现的位置
func indexOfOne(num:Int) -> Int {
var number:Int = num
var pos:Int = 1
while (number & 1) == 0 {
number = number >> 1
pos += 1
}
return pos
}
func isNumberOfPos(num:Int,pos:Int) -> Bool {
// let temp:Int = 1 << (pos - 1)
// return (num & temp) == 0 ? false : true
let number:Int = num >> (pos - 1)
return (number & 1) == 1 ? true : false
}
func findNumberAppearOnce(arr:[Int]) -> (Int,Int) {
var ORNum:Int = 0
for i in 0..<arr.count {
ORNum = ORNum ^ arr[i]
}
let position:Int = indexOfOne(num: ORNum)
var first:Int = 0
var second:Int = 0
for i in 0..<arr.count {
if isNumberOfPos(num: arr[i], pos: position) {
first = first ^ arr[i]
} else {
second = second ^ arr[i]
}
}
return (first,second)
}`</code></pre>
测试代码:
<pre><code>var searchArr:[Int] = [2,4,4,7,3,2,5,5] var searchResult:(Int,Int) = searchNumber.findNumberAppearOnce(arr: searchArr) print("FlyElephant-\(searchArr)出现一次的两个数字---\(searchResult)")</code></pre>
